Food holding device, method of making, and method of storing cooked food

ABSTRACT

A food holding device includes a holding bin and an optional heating component. The holding bin has a specified average surface roughness Ra on at least a portion of the surface intended to be contacted with food during storage of the food.

FIELD OF THE INVENTION

The present invention relates generally to a food holding device andmore particularly to a food holding device with an improved surfacefinish that facilitates storing and maintaining food at an appropriateelevated temperature.

BACKGROUND OF THE INVENTION

In many restaurants, some food is prepared prior to serving and needs tobe stored prior to serving while maintaining the temperature of thecooked food. It is advantageous to be able to maintain a steady anduniform temperature of the cooked food. This is especially the case withcertain types of cooked food, such as French fries, for example.Typically, French fries and similar types of foods are cooked by fryinga suitable portion amount in heated cooking oil in a fry basket. Aftercooking, the cooking oil is allowed to drain from the French fries andtypically the French fries are then stored in a holding bin until aquantity of French fries is required to fill a customer's order.Typically, the French fries are stored in a heated holding bin made ofstainless steel and heated by a heat lamp. The radiant energy from theheat lamp is absorbed by the French fries contained in the holding bin.However, a holding bin that has a standard stainless steel foodappliance surface of the holding bin adjacent French fries is relativelycool in the presence of heat lamp radiation, which is not optimum forstorage of French fries as some of the stored French fries will contactthe relatively cool stainless steel surface and others will not,resulting in a temperature disparity. This effect can be more pronouncedas French fries are removed from the bin to fill orders and portions ofthe bottom surface of the bin are exposed, particularly as tosingle-layer or individual French fries that are exposed to or incontact with such bin surfaces. A need exists for a heated French frystorage bin having an optimal surface for maintaining French fries in auniform heated state during storage including as French fries areperiodically removed and added to the bin, alternately exposing more andless of the holding bin surface.

SUMMARY OF THE INVENTION

One embodiment of the present invention comprises a food holding deviceincluding a holding bin and optionally a heating component. Cooked fooditems can be stored in the holding bin of the food holding device. Whileit is contemplated that typically the food contained in the holding binwill be heated by a heating component, such as an infrared heat lamp,for example, the heating component does not need to form part of thefood holding device in accordance with the invention.

In accordance with the invention, a surface or surfaces of the holdingbin intended for contact by the food stored therein will have a surfaceroughness as hereinafter described. It is to be understood that othersurfaces of the food holding device may also have such surface roughnessif desired.

In one embodiment, at least a portion of the food contacting exposedsurfaces of the holding bin have an average surface roughness Ra in therange of from about 0.5 μm to about 3 μm and more particularly fromabout 0.75 μm to about 2 μm and more preferably in the range of fromabout 0.75 to about 1.75 μm. For example, for any embodiment of theinvention, the average surface roughness may be up to a maximum of about1.2 μm. As used herein, the term surface roughness is a measure of thetexture of a surface, quantified by the vertical deviations of a realsurface from a perfectly uniform surface. As used herein, “averagesurface roughness Ra” and “surface roughness Ra” means the roughness ofa surface that is the absolute value arithmetic average surfaceroughness of a surface.

In another embodiment, the bottom portion of the holding bin comprisesperforations and an average surface roughness Ra in the range of fromabout 1.0 μm to about 1.75 μm. The desired surface roughness Ra can beobtained by any suitable method including, for example, by abrading,polishing or by bead blasting, as will be known to those skilled in theart and depending on the condition of the starting surface.

If present, the heating component of the food holding device providesheat to approximately maintain the temperature of cooked food stored inthe food holding device. In one embodiment, the heating componentcomprises a radiant heat source, typically being at least one infraredheat lamp. The heat lamp may comprise at least one frosted bulb.

In a specific embodiment, the bottom portion can be heated to an averageelevated temperature typically in the range of from about 165° F. toabout 175° F. The bottom portion may have cooked food stored thereon.The cooked food may maintain an approximately uniform temperature. Inone embodiment, the cooked food is any fried food, such as, for example,French fries or chicken nuggets.

In another embodiment of the invention, a method of storing cooked foodis provided. In one embodiment, cooked food is placed in a food holdingdevice comprising a bin portion and a heating component, wherein thebottom portion comprises an average surface roughness Ra in the range offrom about 0.5 μm to about 3 μm and more particularly from about 0.75 μmto about 2 μm. In another embodiment, the bottom portion comprises anaverage surface roughness Ra in the range of from about 1.0 μm to about1.75 μm. In another embodiment, the surface roughness Ra of the bottomportion is obtained by bead blasting. Preferably, the stored cooked foodmaintains an approximately uniform temperature. During use, a thin filmof cooking oil is formed on the roughened surface, enabling furtherabsorption of the radiant energy from the heat lamp(s).

In a further embodiment, a method of making a food holding devicecomprises providing a sheet of material suitable for a holding bin, atleast a portion of the sheet of material having an average surfaceroughness Ra in the range of from about 0.5 μm to about 3 μm; forming afood holding bin having a food contacting surface from the sheet ofmaterial so that at least a portion of the food contacting surface hasthe specified average surface roughness of about 0.5 μm to about 3 μmand more particularly in the range of from about 0.75 μm to about 2 μm.In another embodiment, the bottom portion is bead blasted to an averagesurface roughness Ra in the range of from about 1.0 μm to about 1.75 μm.For example, for any embodiment of the invention, the average surfaceroughness may be up to a maximum of about 1.2 μm. The bead blasting maycomprise subjecting the bottom portion to a stream of round glass beadshaving an average grit size of 6 to 80 (about 5 to 70 USS mesh (USSmeans United States Standard Sieve screen size)) at a sufficientpressure to provide the desired surface roughness of the particularmaterial being treated. Any suitable blasting media can be used as longas the desired surface roughness is achieved.

In a specific embodiment, the heating component comprises a radiant heatsource, which may be at least one heat lamp. Typical heat sources areinfrared heat lamps. In another embodiment, the bottom portion isperforated and comprises at least two trays, and the heating componentcomprises four heat lamps, the heat lamps comprising frosted bulbs.

These and other features of the present invention will be bestunderstood from the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the invention will becomeapparent to those skilled in the art from the following detaileddescription of the currently preferred embodiment. The drawings thataccompany the detailed description can be briefly described as follows:

FIG. 1 illustrates a perspective view of a food holding device of thepresent invention;

FIG. 2 illustrates a side elevation view of a food holding device of thepresent invention;

FIG. 3 illustrates a perspective view of a bottom portion of a foodholding device of the present invention; and

FIG. 4 illustrates a perspective view of a heating component of a foodholding device of the present invention.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate a typical food holding device 10 in accordancewith the invention. Food holding device 10 as illustrated is especiallysuited for holding cooked food such as French fries and chicken nuggets,for example. Food holding device 10 includes a food holding portion 12and a heating component 14 housed in a cabinet 11. Food holding portion12 includes holding bin 15 composed of a tray 16 a-b, sidewalls 18 a-b,a bin divider 20, and a bottom surface 22 a-b of tray 16 a-b.

Tray 16 a-b may contain perforations 24 as desired. Perforations 24allow oil and/or any liquid to drip from and small solid food particlesto be separated from any food stored within food holding device 10,thereby helping to maintain the crispness and uniform quality of thefood. Typically, perforations are circular and are from about 0.1 inchesto about 0.5 inches in diameter, although it is to be understood thatany suitably shaped and sized perforations may be used, which can berelated to the size and type of food to be stored therein, as will beappreciated by those skilled in the art.

Food holding portion 12 includes the at least one tray 16 a-b and caninclude bin divider 20. Food holding portion 12 does not always includea bin divider 20 or may include multiple tray dividers to formadditional compartments in food holding portion 12. Food holding portion12 as illustrated includes an optional one bin divider 20. This providestwo holding areas for food items.

Food holding portion 12 can comprise any appropriate material that willabsorb heat, such as anodized aluminum or stainless steel. Typically,the bottom portion comprises stainless steel.

Heating component 14 comprises a heating element to heat food holdingportion 12. The heating element may be any appropriate heating element.In one embodiment, the heating element comprises heat lamps 26 a-b. Theheating element may comprise at least one heat lamp and may comprise asmany heat lamps 26 a-b as desired to obtain a desired appropriatetemperature of food holding portion 12. Heat lamps 26 a-b may compriseany type of bulb, such as clear lamps or frosted lamps. In oneembodiment, heat lamps 26 a-b each comprises a frosted infrared heatlamp.

Tray 16 a-b, including bottom surface 22 a-b comprises an averagesurface roughness Ra in the range of from about 0.5 μm to about 3 μm andmore typically from about 0.75 μm to about 2 μm. In another embodiment,the bottom surface comprises an average surface roughness Ra in therange of from about 1.0 μm to about 1.75 μm. For example, for anyembodiment of the invention, the average surface roughness may be up toa maximum of about 1.2 μm. Any appropriate method may be utilized toobtain the desired average surface roughness. For example, bottomsurface 22 a-b may be polished or bead blasted to obtain the desiredaverage surface roughness. Typically, bottom surface 22 a-b is beadblasted to obtain an average surface roughness Ra of betweenapproximately 0.75 μm and approximately 2 μm. The surface roughness Racan be measured with a profilemeter as is known in the art. Typically,at least the portion of holding bin 15 that contacts food, is intendedto contact food or typically contacts food during use, will have thesurface roughness Ra as described herein.

Bottom surface 22 a-b absorbs heat from heat lamps 26 a-b. The averagesurface roughness Ra is in the range of from about 0.5 μm to about 3 μmand more particularly from about 0.75 μm to about 2 μm typically resultsin a bottom surface that is on average 11° F. hotter than a standardpolished tray for a typical heating lamp arrangement used to maintaincooked French fries at elevated temperature just prior to serving themto a customer. Bottom surface 22 a-b absorbs heat such that when cookedfood F is added to food holding portion 12, cooked food F does not losea significant amount of heat to bottom surface 22 a-b. Cooked food Fmaintains a more uniform temperature throughout the cooked food storedin food holding portion 12, resulting in overall hotter cooked food. Theexposed surfaces of sidewalls 18 a-b and bin divider 20 may, if desired,also have a surface roughness Ra similar to that of bottom surface 22a-b, as illustrated with respect to the sidewalls shown in FIG. 3.

Cooked food F is contained within food holding portion 12. Cooked food Fas illustrated is French fries and can be any cooked food desired to bestored in food holding device 10, such as French fries, hash browns,onion rings, fried mushrooms, hamburgers, chicken, or any other fooditem. In one embodiment, cooked food F is French fries. Cooked food F ismaintained at an approximately uniform temperature throughout, and doesnot lose a significant amount of heat to bottom surface 22 a-b.

FIG. 3 illustrates a bottom portion 40 of a food holding device inaccordance with another embodiment of the invention. Bottom portion 40includes a tray 42, at least two sidewalls 44 a-b, a back portion 46,and a bottom surface 48.

Bottom surface 48 typically comprises perforations 50. Perforations 50allow small particulate matter, oil and/or any liquid to drip from anyfood stored within bottom portion 40, thereby helping to maintain thecrispness and consistency of the food. Typically, perforations arecircular and are typically in the range of 0.1 to about 0.5 inches indiameter, although it is to be understood that any suitably shaped andsized perforations may be used, which can be related to the size andtype of food to be stored therein, as will be appreciated by thoseskilled in the art.

Bottom portion 40 can comprise any appropriate material for contact withfood that will absorb heat, such as anodized aluminum or stainlesssteel. Preferably, the bottom portion comprises stainless steel.

Tray 42, including bottom surface 48, comprises an average surfaceroughness Ra in the range of from about 0.5 μm to about 3 μm and moreparticularly from about 0.75 μm to about 2 μm. In a more particularembodiment, bottom surface 48 comprises an average surface roughness Rain the range of from about 1.0 μm to about 1.75 μm. For example, for anyembodiment of the invention, the average surface roughness may be up toa maximum of about 1.2 μm. Any appropriate method may be utilized toobtain the desired average surface roughness. For example, bottomsurface 48 may be polished or bead blasted to obtain the desired averagesurface roughness. Typically, the bottom surface is bead blasted toobtain an average surface roughness Ra in the desired range. Optionally,and as shown in FIG. 3, sidewalls 44 a and 44 b have a surface roughnessRa similar to the surface roughness of bottom surface 48.

Bottom surface 48 can absorb heat. The average surface roughness Ra ofbetween approximately 0.75 μm and approximately 2 μm results in a bottomsurface that is on average 11° F. hotter than a standard polished trayduring normal use (i.e., after bottom surface 48 has a coating ofcooking oil thereon after typical use in storing French fries or otherfried food). Bottom surface 48 absorbs heat such that when cooked foodis added to bottom portion 40, the cooked food does not lose asignificant amount of heat to bottom surface 48. The cooked foodmaintains a more uniform temperature throughout the cooked food storedin bottom portion 40, resulting in overall hotter cooked food.

Typically, back portion 46 does not undergo the same treatment as bottomsurface 48. Back portion 46 can be untreated anodized aluminum orstainless steel. Typically, back portion 46 is standard polishedstainless steel.

FIG. 4 illustrates a heating component 90 of a food holding device inaccordance with another embodiment of the invention. Heating component90 includes a top portion 92 and two side portions 94 a-b. Top portion92 comprises heat lamps 96 a-d. Heat lamps 96 a-d provide heat that canbe used to maintain the temperature of cooked food. Heat lamps 96 a-dcan be either clear glass or frosted bulbs. Typically, heat lamps 96 a-dare frosted bulbs.

In another aspect of the invention, a method of storing cooked food isprovided. The method of storing cooked food includes placing cooked foodin a food holding device. The food holding device includes a bottomportion and a heating component. Typically, the food holding device isthe food holding device as illustrated in FIGS. 1-4.

Returning to FIGS. 1 and 2, cooked food F is placed into food holdingdevice 10. Typically, cooked food F is placed into tray 16 a-b. Heatlamps 26 a-b heat bottom surface 22 a-b. A storage area 13 is providedalong the top of cabinet 11.

Bottom surface 22 a-b absorbs heat such that when cooked food F is addedto food holding portion 12, cooked food F does not lose a significantamount of heat to bottom surface 22 a-b. Cooked food F maintains a moreuniform temperature throughout the cooked food stored in food holdingportion 12, resulting in overall hotter cooked food.

Bottom surface 22 a-b contains perforations 24. Oil and liquid drip fromany food stored within food holding device 10 through perforations 24,thereby maintaining the crispness of the food.

In another aspect of the invention, a method of making a food holdingdevice is provided. The method of preparing a food holding deviceincludes optionally providing a heating component, providing aperforated bottom portion comprising a bottom surface and at least onetray, forming a desired surface roughness, which may be by bead blastingthe bottom surface, to achieve an average surface roughness Ra in therange of from about 0.5 μm to about 3 μm and more particularly fromabout 0.75 μm to about 2 μm. In some embodiments, the bottom surface isbead blasted to achieve an average surface roughness Ra in the range offrom about 1.0 μm to about 1.75 μm.

Returning to FIGS. 1 and 2, the bead blasting includes subjecting thebottom surface 22 a-b to a stream of glass beads at a suitable pressureand for a suitable time to achieve the desired surface roughness. Aswill be appreciated by those skilled in the art, the pressure andduration will depend on many factors, including the type of materialbeing bead blasted, the nozzle type and rate of bead bombardment.

In one embodiment, as illustrated in FIGS. 1 and 2, heating component 14includes at least one heat lamp 26 a-b. In another embodiment, asillustrated in FIGS. 1 and 2, food holding portion 12 includes at leasttwo trays 16 a-b. In a further embodiment illustrated in FIG. 4, heatingcomponent 90 may contain four heat lamps 96 a-d, wherein heat lamps 96a-d include frosted bulbs.

Cabinet 11 may include a storage area 98 covered by doors 100 a, 100 b.Cabinet 11 may also include receptacles 30 which can be used for storageof items, for example, for holding French fry cartons to be filled orother articles as desired. A cabinet storage area 102 is provided alongthe top of cabinet 11, which can be used to hold a salt dispenser 104 asshown in FIG. 1.

EXAMPLES Example 1

A frystation was tested for heat distribution along the bottom surfaceof the bottom portion. The frystation had a width of 36 inches, and wasa non-autosalt frystation. The top portion had four 375 W GE® frosted,non-coated heating lamps with an R40 base. The bottom portion hadmultiple perforations and was bead blasted with glass beads to anaverage surface roughness Ra of about 0.75 μm. Surface temperatures ofthe bottom portion were taken at twelve different points; four equallyspaced points along a back row, four equally spaced points along amiddle row, and four equally spaced points along a front row. Thetemperatures were in a 19° F. temperature range, between 153° F. and182° F., with an average value of 169° F. The data is summarized belowin Table 1.

TABLE 1 Frystation with a Bottom Surface with an Average SurfaceRoughness Ra of about 0.75 μm Surface Temperature (° F.) Back Row 157153 170 169 Middle Row 163 164 182 181 Front Row 180 167 180 179

Comparative Example

A control frystation was tested for heat distribution along the bottomsurface of the bottom portion. The frystation had a width of 36 inches.The top portion had four 375 W Franke® clear, non-coated heating lampswith an R40 base. The bottom portion had multiple perforations and was apolished tray surface. Surface temperatures of the bottom portion weretaken at twelve different points; four equally spaced points along aback row, four equally spaced points along a middle row, and fourequally spaced points along a front row. The temperatures were in a 30°F. temperature range, between 138° F. and 168° F., with an average valueof 158° F. The data is summarized below in Table 2.

TABLE 2 Frystation with a Polished Bottom Surface Surface Temperature (°F.) Back Row 168 165 163 156 Middle Row 161 168 164 166 Front Row 138145 144 156

While the invention has been described with respect to certain preferredembodiments, as will be appreciated by those skilled in the art, it isto be understood that the invention is capable of numerous changes,modifications and rearrangements, and such changes, modifications andrearrangements are intended to be covered by the following claims.

The invention claimed is:
 1. A food holding device comprising: a holdingbin having a food-contacting surface; wherein at least a portion of thefood-contacting surface comprises a bottom surface having an averagesurface roughness Ra in the range of from about 0.5 μm to about 3 μm. 2.The food holding device of claim 1, wherein the bottom surface comprisesperforations and wherein the bottom surface has an average surfaceroughness Ra between the perforations of between approximately 0.75 μmand approximately 2 μm.
 3. The food holding device of claim 1, whereinthe average surface roughness Ra of the bottom surface is obtained bybead blasting.
 4. The food holding device of claim 1, wherein the bottomsurface comprises perforations, and wherein the average surfaceroughness Ra of the bottom surface is obtained by polishing.
 5. The foodholding device of claim 1, wherein at least substantially all of thefood-contacting surface of the holding bin has an average surfaceroughness Ra in the range of from about 0.5 μm to about 3 μm.
 6. Thefood holding device of claim 1, wherein at least substantially all ofthe food-contacting surface of the holding bin has an average surfaceroughness Ra in the range of from about 0.75 μm to about 2 μm.
 7. Thefood holding device of claim 1 further comprising a food holding portioncomprising the holding bin, wherein the material of the food holdingportion is stainless steel.
 8. The food holding device of claim 1further comprising a radiant heat source directed towards the bottomsurface, the surface roughness for enhancing the absorption of radiatedheat from the heat source by the bottom surface.
 9. The food holdingdevice of claim 1 wherein the bottom surface comprises a plurality ofopenings for separating small food particles from food in the holdingbin.
 10. The food holding device of claim 1, wherein at leastsubstantially all of the food-contacting surface of the holding bin hasan average surface roughness Ra in the range of from about 1 μm to about1.75 μm.
 11. The food holding device of claim 10, wherein at leastsubstantially all of the food-contacting surface of the holding bin hasan average surface roughness Ra of up to a maximum of about 1.2 μm. 12.The food holding device of claim 10, wherein all of the food-contactingsurface of the holding bin has an average surface roughness Ra in therange of from about 0.5 μm to about 3 μm.
 13. The food holding device ofclaim 1, further comprising a quantity of cooked food contained in theholding bin.
 14. The food holding device of claim 13, wherein the cookedfood comprises French fries.
 15. A food holding device comprising: aholding bin having a food-contacting surface, wherein at least a portionof the food-contacting surface comprises a bottom surface; and a radiantheat source directed towards the bottom surface; wherein the bottomsurface has an average surface roughness Ra in the range of from 0.5 μmto 3 μm enhancing the absorption of radiated heat from the heat sourceby the bottom surface.
 16. The food holding device of claim 15 whereinthe holding bin comprises an open top permitting radiant heat from theradiant heat source to enter the bin.
 17. The food holding device ofclaim 15 wherein the bottom surface comprises a plurality of openingsfor separating small food particles from food in the holding bin. 18.The food holding device of claim 15 further comprising a food holdingportion comprising the holding bin, wherein the material of the foodholding portion is stainless steel.
 19. The food holding device of claim18, wherein at least substantially all of the food-contacting surface ofthe holding bin has an average surface roughness Ra in the range of from0.75 μm to 2 μm.
 20. The food holding device of claim 18, wherein atleast substantially all of the food-contacting surface of the holdingbin has an average surface roughness Ra in the range of from 1 μm to1.75 μm.
 21. The food holding device of claim 20, wherein at leastsubstantially all of the food-contacting surface of the holding bin hasan average surface roughness Ra of up to a maximum of about 1.2 μm.